As civilizations advanced through the eons, people preferred the use of science over magic, which was slowly forgotten.

In the present day, creatures known as Phantoms attempt to bring humanity to despair, bolstering their ranks by turning "Gates", or people with high levels of magic, into their own kind. A mage named Wizard appears to be humanity's final hope, wielding the powers of long forgotten magic to fight the Phantoms.

The primary antagonists of the series led by Wiseman. They are being born from humans that have high magic potential known as Gates. When a Gate is put into despair, they give birth to a Phantom which they are not considered to be human anymore. They assume the human form they were born from but the human itself exists no more. The current goal of the Phantoms is to create more Phantoms so Wiseman can hold a Sabbath.

From the Arabic word, al ghûl, which means demon. They have prominent demon horns and show up in numbers. They're the grunts of the series. (Sort of explains why Batman's villain Ra's Al Ghul is always called the head of the demons). They are initially rocks until thrown on the ground. The official TV Asahi site spells it as "Ghoul".

People with high levels of magic. That means there's a Phantom inside their Underworld. Phantoms are what give people the ability to use magic.

Underworld

The world within each of us. The setting changes depending on the specific person. This is usually a scene from the person's memory which represents a moment when they were given hope. One reoccurring theme of this series is that there is a fine line between hope and despair. This is particularly evident in the case of Haruto's Underworld.

Hope

The power of this emotion is what gives people the ability to live. It suppresses the Phantom within them. The moment a Gate gives into despair, the Phantom within starts breaking their Underworld, creating purple cracks on the person. At the end of this process, a Phantom is born, taking the original person's memories and personality. This will usually kill the Gate, but there are exceptions.

In Haruto's case, he used his hope to conquer the Phantom within him, which allows him to become a mage.

Toei is releasing Japanese dubs for Power Rangers Mystic Force on DVD at the same time that Wizard is being released.

Except for in previews, opening narration of episode 8, and non-canon movies, Wizard and Beast are never called Kamen Riders. They are instead referred to as mages like ring mage or primordial mage. The word Rider is never mentioned in the show itself.

The first Rider series in a while that Eitoku doesn't portray the second Rider. Due to an injury in August, Eitoku hasn't been able to perform any stunt work.

The majority of Wizard apparently takes place in the fictional Toriisaka district 鳥井坂. It's the name of the police station where Rinko is assigned, and the name shows up in other places in the show. This is very similar to the real Toriizaka 鳥居坂 in Tokyo.

Apparently the magic circles in Wizard mean things! Check this site to see a detailed explanation.

In the last Koyomi's Room segment, Koyomi dresses as a stewardess when she says she wants to know about her past. That's because her actress, Okunaka Makoto, is a member of Agency Passpo. Agency Passpo has a stewardess theme, and most of the girls on their site are dresses as stewardesses.